Pacific pocket mice are not active during normal business hours. These guys like to come out when they are least likely to be seen by many predators, such as owls. In their home cages after “sleeping” all day, Pacific pocket mice keep themselves busy by foraging, remodeling, and cleaning themselves and their nest. To observe these activities and conduct experiments in the lab, we use red light instead of fluorescent light to see. Many rodents, including this coastal heteromyid, can’t see the color red; it is perceived as black.

Well, in this red light we can observe some very interesting activities. Individuals housed next to each other in the facility are divided by a semi-permeable barrier. This barrier, oddly enough, allows an individual to express a behavior seen in the wild: pilfering.

This Pacific pocket mouse kept her seeds on a pile of sand.

Some Pacific pocket mice are pretty messy and leave their seeds all over their cage. Since sand is easily manipulated, neighboring Pacific pocket mice have taken the advantage of collecting seeds from their neighbor’s cages by moving sand through slots in the barriers. An individual can make an avalanche effect that brings stray seeds cascading down toward eagerly awaiting forepaws.

Amaranta Kozuch is a senior research technician at the San Diego Zoo Institute for Conservation Research. Read her previous post, Pocket Mouse Pup Grows Up.